A lot of men, it turns out, get off on having power over women’s bodies, and are willing to bully, coerce, and even trick women into pregnancy to get that feeling of power over them. And anti-choicers are helping them maintain control.

A new pilot study by researchers at the University of California-Davis School of Medicine finds that a simple intervention–asking women visiting family planning clinics about sexual violence and coercion–can dramatically reduce the incidence of a form of intimate-partner violence known as reproductive coercion.

Sexual violence and coercion by intimate partners plays a critical role in unintended pregnancy, the spread of sexually transmitted infections, poor maternal outcomes and in abortion. The problems of violence, control, and contraceptive sabotage are so widespread that public-health advocates see teen pregnancy as a “canary in a coal mine” or one indicator of possible abuse.